meteortools.fileformats.platepar

 1# 
 2# class to read a single or multiple platepar files
 3#
 4# Copyright (C) 2018-2023 Mark McIntyre
 5
 6import json
 7import os
 8import glob
 9
10
11class platepar:
12    """ Load and manage an RMS platepar object, used to map an image to the sky """
13    def __init__(self, plateparfile):
14        """" Create and load a platepar object from a file plateparfile """
15        with open(plateparfile, 'r') as pp:
16            self.jsd = json.load(pp)
17            try: 
18                self.id = self.jsd['station_code']
19                # field of view details
20                self.alt_centre = self.jsd['alt_centre']
21                self.az_centre = self.jsd['az_centre']
22                self.Ho = self.jsd['Ho']
23                self.fov_h = self.jsd['fov_h']
24                self.fov_v = self.jsd['fov_v']
25                self.rotation_from_horiz = self.jsd['rotation_from_horiz']
26                self.RA_d = self.jsd['RA_d']
27                self.dec_d = self.jsd['dec_d']
28                self.pos_angle_ref = self.jsd['pos_angle_ref']
29
30                # camera location
31                self.lat = self.jsd['lat']
32                self.lon = self.jsd['lon']
33                self.elev = self.jsd['elev']
34
35                # camera resolution
36                self.X_res = self.jsd['X_res']
37                self.Y_res = self.jsd['Y_res']
38
39                # Reference time and date
40                self.time = 0
41                self.JD = self.jsd['JD']
42                self.UT_corr =self.jsd['UT_corr']
43
44                # FOV scale (px/deg)
45                self.F_scale = self.jsd['F_scale']
46
47            except:
48                print('invalid json file')
49
50    def getLocation(self):
51        """ get the lat, lon and elevation from the platepar"""
52        return [self.lat, self.lon, self.elev]
53
54    def getView(self):
55        """ get the pointing direction (alt/az), field of view (h/v) and rotation """
56        return [self.altcentre, self.azcentre, self.fov_h, self.fov_v, self.rot]
57
58    def getResolution(self):
59        """ Get the reported camera resolution """
60        return [self.xres, self.yres]
61
62
63def loadPlatepars(fldr):
64    """ Create a dictionary of multiple platepars  
65    
66    Arguments:  
67        fldr:   [string] A folder containing one or more platepar files  
68
69    Returns:  
70        a json dict containing each platepar indexed by the corresponding filename  
71    """
72    platepars ='{'
73    pth = os.path.join(fldr, '*.json')
74    pps = glob.glob(pth)
75    for pp in pps:
76        thispl = platepar(pp)
77        if thispl is not None:
78            if len(platepars) > 1: # and pp != pps[-1]:
79                platepars = platepars + ','
80            platepars = platepars + '"' + thispl.id +'": '+ json.dumps(thispl.jsd)
81    platepars = platepars + '}'
82    #print(platepars)
83    ppjson = json.loads(platepars)
84    return ppjson